Development and validation of an instrument to evaluate medical students’ lifestyle

Introduction It is required to have validated instruments in health science students that identify unhealthy habits and assess the impact of educational interven-tions and programs aimed at promoting a healthy lifestyle. Objective To evaluate the validity and reliability of an instrument to measure medical students' lifestyles. Methods A lifestyle questionnaire was developed using the Delphi technique by a group of experts. The final questionnaire was applied to 332 students of the School of Medicine of the Ricardo Palma University in 2017. A preliminary examination was carried out to assess preconditions for construct validity—including the correlation matrix, the Kaiser Meyer Olkin statistic, and the Bartlett sphericity test. Factor analysis was used for construct validity, and the possible resulting factors were extracted through the principal component analysis. Cronbach's alpha coefficient was calculated to assess the instrument reliability. Results In this study, 41.6% of participants were men with a mean age of 20 years (standard deviation = 3). The preconditions for the factor analysis were a Kaiser Meyer Olkin coefficient = 0.773 and a significant Bartlett sphericity test. For the 47 items of the final questionnaire, the factor analysis showed an explained variance of 56.7% with eigenvalues greater than one. Cronbach's alpha was 0.78. The final questionnaire could assume values between-23 to 151 points. Based on a cut point of 71 points, the prevalence of students with an unhealthy lifestyle was 73.6%. Conclusion The developed instrument has acceptable validity and reliability to measure lifestyle in medical students. For external validation, studies in other university populations are suggested.